MCQ objective Questions on Engineering Mechanics - Set 20

Practice Test: Question Set - 20

1. Which
of the following is an equation of linear motion?(where, u and v =
Initial and final velocity of the body, a = Acceleration of
the body, and s = Displacement of the body in time t seconds.)

(A) v = u + a.t

(B) s = u.t +
½ a.t2

(C) v2 = u2+ 2a.s

(D) All of these

Answer: Option D

2. Moment of
inertia of a hollow circular section, as shown in the below figure about X-axis,
is

(A) π/16
(D² - d²)

(B) π/16
(D³ - d³)

(C) π/32
(D⁴ - d⁴)

(D) π/64
(D⁴ - d⁴)

Answer: Option D

3. The
forces which do not meet at one point and their lines of action do not lie on
the same plane are known as

(A) Coplanar
concurrent forces

(B) Coplanar
non-concurrent forces

(C) Non-coplanar
concurrent forces

(D) None
of these

Answer: Option D

4. Concurrent
forces are those forces whose lines of action

(A) Lie on the
same line

(B) Meet
at one point

(C) Meet
on the same plane

(D) None
of these

Answer: Option B

5. The moment
of inertia of a solid cylinder of mass 'm', radius 'r' and
length 'l' about the longitudinal axis or polar axis is

(A) mr2/2

(B) mr2/4

(C) mr2/6

(D) mr2/8

Answer: Option A

6. According
to parallel axis theorem, the moment of inertia of a section about an axis
parallel to the axis through center of gravity (i.e. IP)
is given by(where, A = Area of the section, IG =
Moment of inertia of the section about an axis passing through its C.G.,
and h = Distance between C.G. and the parallel axis.)

(A) IP = IG + Ah2

(B) IP = IG - Ah2

(C) IP = IG / Ah2

(D) IP = Ah2 / IG

Answer: Option A

7. The law of
the machine is (where P = Effort applied to lift the
load, m = A constant which is equal to the slope of the
line, W = Load lifted, and C = Another
constant which represents the machine friction.)

(A) P = mW - C

(B) P = m/W + C

(C) P = mW + C

(D) P = C - mW

Answer: Option C

8. The
wheels of a moving car possess

(A) Potential
energy only

(B) Kinetic
energy of translation only

(C) Kinetic
energy of rotation only

(D) Kinetic
energy of translation and rotation both

Answer: Option D

9. The
resultant of two equal forces ‘P’ making an angle ‘θ’, is
given by

(A) 2Psinθ/2

(B) 2Pcosθ/2

(C) 2Ptanθ/2

(D) 2Pcotθ/2

Answer: Option B

10. The
coefficient of restitution for inelastic bodies is

(A) Zero

(B) One

(C) Between
zero and one

(D) More than
one

Answer: Option A

11. If a number
of forces are acting at a point, their resultant will be inclined at an angle 'θ' with the horizontal, such that

(A) tanθ = ΣH/ΣV

(B) tanθ = ΣV/ΣH

(C) tanθ = ΣV ×
ΣH

(D) tanθ = √(ΣV
+ ΣH)

Answer: Option B

12. The periodic
time of a particle with simple harmonic motion is _________ proportional to
the angular velocity.

(A) Directly

(B) Inversely

(C) Square root

(D) None of
these

Answer: Option B

13. The
efficiency of a screw jack is maximum, when (where α = Helix angle, and φ =
Angle of friction.)